Mold-design and improvement of an automatic expansible side paperboard bag folding and gluing machine

ABSTRACT

This utility model corresponds to a special mold-design used to manufacture paperboard bags. The mold-design is a piece of creased paper, which makes it possible for a modified gluing-folding machine to perform a series of liner steps to finish the bag, the process ending with the step in which the product is rotated to glue the bottom. The process is fully automated.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a mold-design to manufactureexpansible-side paperboard bags using a fully automatic gluing/foldingmachine.

[0003] 2. Description of the Prior Art

[0004] Over the years, paper bags or bags made with natural cellulosefor various uses, have been manufactured using traditional methods.

[0005] Originally, molds were made, on which bag makers would cut sheetsof paper to different sizes to manually fold the pieces of material fromwhich the bags would in turn be made. Then, the folds were made and wereimmediately pressed down into bag shape.

[0006] The bottoms of the bags were, and in some cases still are, glued,or a piece of any thicker material is simply placed at the bottom toprevent the bottom from splitting and prevent the bag's contents fromfalling out.

[0007] Most bags are manufactured with a conventional gluing-foldingmachine, which is available to the general public. The machine performshalf of the manufacturing process, and the bags are hand finished byexperienced personnel.

[0008] The advantage of this mold-design and improvement of theexpansible-side paperboard bag folding-gluing machine is that the entiremanufacturing process is automated, eliminating the need for manuallabor. The bag mold-design is placed on the machine by an automaticfeeder and the only manual work required is fitting the string handleand packing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0009] The mold-design for the bag manufacturing process using thecreased paperboard mold-design, with a modified folding-gluing machineis described below, illustrating the various steps in the process withthe following figures:

[0010] The mold design used to make the bag is a mold with afour-section structure (FIG. 1.1); the first section is the upper lapand its opposite side is called the upper face; the second section isthe side lap and its opposite side is called the left-hand expansibleside; the third section is the lower lap and its opposite side is calledthe lower face; and the fourth section is the side lap and its oppositeside is called the right-hand expandable side. The latter sectionincludes a gluing stub, and the side laps are creased down the middle sothat they can be easily folded.

[0011] The bags are also creased along the side laps and between theupper and lower laps. The edges of the upper and lower laps are cut onan angle, and the edges of the side laps are cut at a right angle, witha small diagonal cut where they meet the edge of the upper or lowerlaps, and the laps are creased along with their entire length, thecreasing of all laps allowing for suitable fold when gluing the bags. Onthe side opposite the cuts, the mold-design section is straight, withonly four holes used to insert two pieces of string to be used ashandles.

[0012] Once the mold design (FIG. 1.1) is ready, an automatic feeder(FIG. 2.1) places it on the machine.

[0013] The product immediately enters the machine on conveyer belts(FIG. 2.2) that guide the bag mold/design to the folding guides (FIG.2.3). These guides fold the right-hand expansible side along its entirelength, using the crease at the center of the expansible sidemold-design.

[0014] Immediately thereafter, a strategically placed hook pulls thegluing stub and when the hook passes the mold-design, a magnet returnsit to its original position. A smaller guide is used to ensureconsisting folding. Simultaneously with steps 2 and 3, a folding guidefolds the entire length of the left-hand expansible side.

[0015] In order to obtain a uniform, even fold along the length of theexpansible sides, the mold-design passes through a compression band thatkeeps the folds compressed, and keeping the right and left-handexpansible sides and the right-hand lap completely flat (FIG. 3.1).

[0016] An electric eye determines the part of the side gluing stub onwhich glue will be applied, and then shoots the glue automatically,leaving a hot layer on the bag side or gluing stub.

[0017] Simultaneously with the preceding action, the upper half of thebag and the upper lap are folded by a bouncing belt (with an up and downmovement) and are then joined to their counterparts, permitting adhesionto the gluing stub. Due to the type of flue used, this bond dries almostimmediately.

[0018] The bag is immediately removed on a special conveyer belt thatraises the upper lap of the bottom with a hook that keeps the lap foldedbackwards. When the upper lap of the base is folded, it pulls the leftand right-hand expansible sides leaving two triangles on each side wherethe bottom will be, the side laps and the upper and lower laps.

[0019] An electric eye then enters, detects the product, sees how theupper lap of the bottom is kept raised, and with an insertion attachmentinserts a square or rectangular bottom (FIG. 4.1), depending on theshape of the finished bag, which should be equal or similar to thesurface area of the bag's bottom, for added strength. This additionalbottom section is optional.

[0020] The product enters a second automatic feeder, which sends the bagon to special belts on which the bottom side laps are folded. Thesesidelaps fall on or cover the triangles formed by folding the expansiblesides so that the previously placed bottom section is placed correctly.

[0021] An electric eye immediately detects the product and an automaticinjector shoots glue onto the already folded side sections.

[0022] A hook pulls the upper lap of the bottom section to ensure thatit is glued where the glue was applied, covering half of the bottom, inother words, half of each side lap, and at the same time, the previouslyplaced bottom section is adjusted.

[0023] The product then passes through a speed differential and isrotated 90 degrees from right to left on the conveyer belts, so that itcontinues rotating in the same direction as the belt, but in a differentposition. Thus, the last part of the gluing process can be completedwithout rotating 90 degrees, without which bag manufacture would not bepossible.

[0024] A last electric eye detects the bag and shoots hot glue along thewidth of the bottom section.

[0025] The lower lap of the bottom section (FIG. 5.1) is folded by aguide belt system that moves the lap upwards. The lap is then gluedautomatically to complete the gluing and folding process (FIG. 5.1).

[0026] The bag then enters a drying tunnel where the drying process iscompleted.

[0027] It should be pointed out that the entire process is linear, whichmeans that the product is produced at a low cost.

[0028] At the end of the drying tunnel, the bags pass on to a table.

[0029] Quality control is applied on this table.

[0030] String handles are attached to the finished bag.

[0031] If the product passes the quality control test, it is sent forpacking.

[0032] The gluing-folding machine is described below, and the aspectsthat differentiate it from conventional machines are also described:

[0033] The first part of the machine is designed to produce pre-foldedlinearly glued boxes, boxes with internal compartments, pillow boxes,double-wall boxes and retail products with special finishes. Thismachine has a circulation tunnel through which the product passes inforty seconds. It also has an attachment that handles final folding ofthe product, giving it great versatility for processing custommanufactured products.

[0034] The second part of the machine is the gluing-folding section,which has a circuit with special features in the rear section for finalproduct assembly.

[0035] It also has the following special attachments:

[0036] An automatic compressed air suction feeder;

[0037] An automatic attachment to manufacture boxes with a bottomsection;

[0038] Re-directing unit which rotates the product 90 degrees forfinishing;

[0039] A special inserter that makes it possible to insert the bottomduring the

[0040] folding and gluing process to make the base of the productstronger;

[0041] A fast-drying hot glue application system;

[0042] A central control system.

What is claimed is:
 1. Mold-design and improvement for an automaticexpansible side paperboard bag folding-gluing machine, characterized bythe need for a special creased mold-design to make the bag, consistingof: the mold-design used to make the bag comprises four sections: thefirst is the upper lap, the other side of which is called the upperface, the second section is the side lap the other side of which iscalled the left-hand expansible side, the third section is the lowerlap, the other side of which is called the lower face and the fourthsection is the side lap, the other side of which is called theright-hand expansible side; this section includes a gluing stub; theside laps are creased down the middle for ease of folding; the side lapsbetween the upper and lower lap are also creased; three angle cuts withdiagonal ends are made between these parts in the internal section ofthe angle and it is creased along its entire length; creasing of allparts means the appropriate folds can be made for subsequent gluing; andon the other side of the cut, the mold-design section is straight andhas only four holes into which two pieces of string can be inserted forhandles.
 2. Mold-design and improvement for automatic expansible sidepaperboard bag folding-gluing machine, as per clause 1, this machine'sdistinguishing feature is that to make the fold it is necessary that itscomponent parts be creased in order to finish the bottom.
 3. Mold-designand improvement for automatic expansible side paperboard bagfolding-gluing machine as per clause 1, characterized by the fact thatthe bottom is folded by forming triangles at the base using the sides ofthe bag.
 4. Mold-design and improvement for automatic expansible sidepaperboard bag folding-gluing machine, as per clause 1, characterized bythe following special attachments: automatic compressed air suction feedunit, attachment to manufacture boxes with automatic bottom,re-positioning unit, which rotates the product in process 90 degrees forfinishing, special inserter that inserts the bottom during the foldingand gluing process in order to make the base of the product stronger, ahigh-speed hot glue application system, and a central control system. 5.Mold-design and improvement for automatic expansible side paperboard bagfolding-gluing machine, as per clause 4, characterized by an automaticfeeder, conveyer belts and folding guides.
 6. Mold-design andimprovement for automatic expansible side paperboard bag folding-gluingmachine, as per clause 4, characterized by special hooks that guide thelaps and expansible sides to ensure that they are placed as needed andthat they remain folded long enough to manufacture the bag. 7.Mold-design and improvement for automatic expansible side paperboard bagfolding-gluing machine, as per clause 4, characterized by the fact thatit uses a speed differential on the conveyer belts to rotate the product90 decrees in the last stage of the gluing process.
 8. Mold-design andimprovement for automatic expansible side paperboard bag folding-gluingmachine as per clause 2, characterized by the fact that the bottom isfolded by forming triangles at the base using the sides of the bag. 9.Mold-design and improvement for automatic expansible side paperboard bagfolding-gluing machine, as per clause 2, characterized by the followingspecial attachments: automatic compressed air suction feed unit,attachment to manufacture boxes with automatic bottom, re-positioningunit, which rotates the product in process 90 degrees for finishing,special inserter that inserts the bottom during the folding and gluingprocess in order to make the base of the product stronger, a high-speedhot glue application system, and a central control system. 10.Mold-design and improvement for automatic expansible side paperboard bagfolding-gluing machine, as per clause 2, characterized by the followingspecial attachments: automatic compressed air suction feed unit,attachment to manufacture boxes with automatic bottom, re-positioningunit, which rotates the product in process 90 degrees for finishing,special inserter that inserts the bottom during the folding and gluingprocess in order to make the base of the product stronger, a high-speedhot glue application system, and a central control system. 11.Mold-design and improvement for automatic expansible side paperboard bagfolding-gluing machine, as per clause 5, characterized by special hooksthat guide the laps and expansible sides to ensure that they are placedas needed and that they remain folded long enough to manufacture thebag.
 12. Mold-design and improvement for automatic expansible sidepaperboard bag folding-gluing machine, as per clause 6, characterized bythe fact that it uses a speed differential on the conveyer belts torotate the product 90 decrees in the last stage of the gluing process.